Seasonal monsoons and diverse topography significantly influence Cambodia's economy (see Environment , ch. 2). The southwest monsoon brings the rainy season (May to October), which is suitable for planting and growing the rice seedlings, and the northeast monsoon sends back dry air (November to March), which makes possible the paddy harvest.
The country's lakes and rivers also affect the economy. They are an abundant source of fish, a mainstay of the Cambodian diet, and they make possible irrigated agriculture, on which the country depends for its livelihood (see Climate , ch. 2). The principal waterway, the Mekong River, is an important trade route and avenue of communication. Since ancient times, the Tonle Sap (Great Lake), the Tonle Sab and the Mekong rivers, and their tributaries have been centers of economic and political power. Phnom Penh--the site of the royal residence, the administrative capital, and, in general, the locus of power, of culture, and of business--is situated at the junction of the Tonle Sab and the Mekong.
Data as of December 1987